Reamer-frame



R. S. MAcEWAN.

REAMER FRAME.

APPLICATION FILED Nov.2s. 1919.

1,339, 1 1 8. Patented y 4, 1920.

CDC) \3 I ATENT OFFICE.

ROBERT S. MACEWAN, 01b TROY, NEW YORK.

BEAMER-FRAME.

Specification of Letters Patent.

Patented May 4, 1920.

. Application filed November 26, 1919. Serial No. 340,961.

(FILED UN 'DER THE ACT OF MARCH 3, 1883, 22 STAT. L, 625.)

To all whom it may concern;

Be it known that I, ROBERT a citizen of the United States, of Troy, county of Rensselaer, New York, in Reamer-Frames, is a specification.

The invention described herein may be used by the Government, or any of its ofhcers or employees in rosecutionof work for the Government, or by any other person 111 the United States, without payment of any royalty thereon.

This invention relates to improvements in reamer frames and is particularly adapt- S. MAOEWAN,

State of of which the following ed for holding reamers used in boring guns, I

but is also of general application where accuracy and almement 1S necessary such as in the boring and reaming of engine cylinders.v

In placing a new lmer in guns, the bore of the gun is reamed to a taper which must be true and uniform. Previous to this operation, however, the gun is bored so as to form a series of steps of cylinders having different diameters, which increase in diameter toward the breech end. Each step is usually about 30 inches long. Thesecylindrical portions are bored by means of a boring bar which is well supported at each end and intermediately in order that the axes of the different cylinders may be in alinement.

In using reamers, unless the body of the reamer is supported and guided, it is difiicult to hold it exactly in line with the bored hole and my invention has also in View a means for guiding the reamer which will then produce accurate work. This is accomplished by a reamer frame of simple construction which can be readily applied to position.

In the following description, reference is made to the accompanying drawings in which Figure 1 is an end elevation of my reamer frame with the reamer body shown in section; and

Fig. 2 is a sectionof Fig. 1 on the lines 2-2.

The numeral 1 designates the body of the reamer, which projects in front of the cutting edges and will be herein termed a pilot. To opposite parallel sides of the pilot 1, are applied the'two segments 2, 3 of a holding frame. This frame may be of any suitand a resident have invented an Improvement able material but is preferably cast iron or steel and is machined to present finished surfaces'to the sides of the pilot 1. The frame parts 2, 3 each comprise a rim portion, a hubportion 10 and spokes 11 which extend radially from the hub portion and support the rimat equally spaced intervals.

The spokes 11 are reduced in weight. by

means of the open spaces formed therein as shown in Fig. 2.

The frame parts 2, 3 are formed with a plurality of lugs 4 projecting from the rim portion, which are machined to form shoulders 5 and 6 at right angles to each other. In the recess formed by the shoulders 5 and 6, wood or fiber blocks 7 are inserted. These wood blocks are secured to the frames 2 and 3 by means of screw bolts 8. A lug 4 pro jects from the rim at each spoke 11 so that the lugs are uniformally spaced about the circumference. The end spokes of each segment extend from the hub portion 10 in opposite directions so as to form a chord for the segment.

The two segments of the frame are secured to the pilot 1 by meansof bolts '9 which pass through the end spokes of each segment. When mounted on the pilot 1, the segments conform to the circumference of a complete circle. The wood blocks 7 are cut so that when assembled they conform to the circumference of a circle of the desired diameter. Owing to the different diameters of the steps previously machined in boring the gun, it is necessary to have a plurality of sets of blocks 7 to fit these various diameters. It can be seen that these blocks can be readily changed by simply unscrewing the bolts that secure the blocks in position and replacing them with new blocks of thedesired dimensions.

In reaming the bore of the gun, the blocks 7 are selected to give a diameter that will snugly fit the next cylindrical step and thereby act as a pilot bushing in front of the reamer and assure that the reamer will cut a true taper without variation. It will be understood that this invention can also be applied in reaming a simple cylinder of uniform diameter since it will act as a pilot in starting the reamer, and also guide it during operation.

This is important in View of the fact that it is very difiicult to locate a reamer exactly in line with a bored hole because of slight variations in the indexing of the turret, or

errors resulting from .the guide-ways or 7 other important parts of the machine. By having a pilot bushing of the typeherein described, in front of the reamer, such errors are effectually eliminated.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is

1. A reamer frame comprising a plurality of. parts adapted to support guideblocks, said parts, when assembled to the reamer frame,conforming to the circumference of a circle.

23A reamer frame comprising segmental parts having projecting lugs, means for securing guide blocks in said lugs and means for securing said segmental parts to the,

reamer. body.

, 3. A reamer frame comprising segmental sections adapted to be secured to the reamer body, lugs projecting from said segmental parts and. guide blocks secured in said lugs whereby said reamer body is guided and supported in front of the reamer blades.

4. A reamer frame comprising segmental sections adapted to be secured to a reamer body, a plurality of lugs projecting from said segmental sections, each lug having a shoulder formed therein, a guide block abutting said shoulder andm'eans for securing the blocks to said lug.

V 5. Areamer frame comprisingsegmental sectionsflhaving a hub portion, a rim portion, spokes. extending radially from said hub portion for supporting said rim, aaplu-rality of lugs; projecting from said rim portion, Wood blocks'detachably secured to said lugs and means for securing said sections to the body of areamer.

ROBERTS. MAGEWAN. 

